Machine for cleaning pallets



July 23, 1957 v FRESE MACHINE FOR CLEANING PALLETS 2 Sheets-Sheet 1 Filed Sept. 27. 1954 INVENTOR.

Verne Frese July 23, 1957 v. FRESE 2,799,879 MACHINE FOR CLEANING i-ALLETS Filed Sept. 27, 1954 2 Sheets-Shget 2 unnnjy INVENTOR. Verne Frese United States Patent MACH-ENE FQR CLEANHJG PALLETS Verne Frese, Seattle, Wash.

Application September 27, 1954, Serial No. 458,493

3 Claims. (Cl. 1593) This invention relates to a machine for cleaning pallets, particularly pallets used in the production of concrete products. For its general object the invention aims to provide a machine by which hardened residue portions of concrete adhering to the surface of pallets on which concrete products have been formed can be removed with ease and expedition.

With this and other more particular objects and advantages in view and which will appear and be understood in the course of the following description and claims, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Figure 1 is a top plan view illustrating a machine constructed to embody the preferred teachings of the present invention.

Fig. 2 is a side elevational view thereof.

Fig. 3 is a fragmentary longitudinal vertical sectional view drawn to an enlarged scale on line 33 of Fig. 1 and incorporating a broken-line showing of a number of pallets which are to be cleaned.

Fig. 4 is a transverse vertical section on line 44 of Fig. 3.

Fig. 5 is a fragmentary enlarged-scale longitudinal vertical sectional view portraying the reciprocally movable carriage of the present invention in process of picking up a pallet from the pallet-holding magazine preliminary to conveying the pallet through a cleaning zone.

Fig. 6 is a fragmentary transverse vertical sectional view on line 6-6 of Fig. 5; and

Fig. 7 is a detail view illustrating the manner in which a carriage-conveyed pallet is enabled to traverse a stopdog whose function is to strip the pallet from the carriage when the carriage returns for another pallet after a cleaning operation has been performed.

According to the present invention the pallets P which are to be cleaned are stacked in a magazine with the incrusted side uppermost. Subjacent to this magazine is a carriage mounted for reciprocatory horizontal movement, and this carriage functions to remove the pallets successively from the bottom of the stack and convey the same forwardly through a cleaning zone. In the path travelled by the pallet as it traverses this zone is a blade which performs a scraping function upon the incrusted face. A detailed description of the frame-work of the machine is unnecessary other than to point out that longitudinal side principles therefor, denoted by the numerals 1t and 11, are each sectionally of a channel shape and have their gutters 12 opposingly disposed. These gutters function as closed track-ways for carriage wheels 13.

The carriage presents at the front a box-like body 14 having a respective one of said wheels disposed at each of the four corners thereof. Being of rectangular plan configuration, moderately smaller in compass than the pallets and with the upper edge lying in a common plane, said box-like body is adapted to have the conveyed pallet ice seat thereon. Projecting rearwardly from the box body as rigid prolongations thereof the carriage provides a pair of vertically slotted reach-arms 15 disposed to occupy positions spaced apart at opposite sides of the carriages longitudinal median line, and journaled in the slots of these reach-arms for free rotation about transverse horizontal axes are rollers 16. The upper surfaces of these rollers project somewhat above the plane occupied by the box-bodys upper edge, the degree of projection being less than the thickness of a pallet.

For moving the carriage between the forward and rear limits of its permitted reciprocatory travel there is provided a hydraulic ram 20 connected by a fork-and-pin attachment 2l22 .to a tonque 23 provided by the carriage adjacent the head end thereof, the cylinder complement of such ram being denoted by 24 and receiving an anchor connection from a frame-carried center pin 25.

The magazine for the pallets is designated by 26 and is an open-bottom affair disposed to overlie the carriage box 14 at the rear extreme of the latters reciprocatory travel. The arrangement is one in which the lowermost pallet in the stack which is contained within the magazine drops by gravity onto the box-body 14 as the latter moves to the rear extreme of its reciprocatory travel. On the back face of the box-bodys rear wall adjacent each side thereof there is provided a respective pair of spaced lugs 27, and fulcrumed as at 28 between these pairs of lugs is a respective uni-directional weighted feedpawl 29 acting, as the carriage reaches the rear extreme of its reciprocatory movement, to lodge behind the rear edge of the lowermost pallet in the stack and then cause the pallet to move forwardly in concert with the forward movement of the carriage. It will be apparent, as the carriage moves forwardly, that the rollers 16 are brought below the magazine and produce a floor holding the lowermost pallet in the stack sufficiently elevated to permit the box-body to enter freely below the same in the box-bodys following return travel.

Denoted by 30, the blade which I employ for scraping the pallets extends transversely of the machine immediately to the front of the magazine and is made integral with yoke-arms 31 which extend rearwardly from each side thereof. Co-axial trunnion pins 32 at the rear ends of these yoke-arms are journaled in pillow blocks 33 carried by the frame, thus permitting the scraper blade to move vertically about the center of the trunnion pins as an axis. A transverse horizontal strongback 34 overlies the blade, being carried by posts 35 rigid with the frame, and received between the blade and the strongback to yieldingly urge the blade downwardly are a plurality of stiff compression springs 36. Nuts 37 working on the threaded upper ends of the posts provide adjustment for the load characteristic of the springs.

I find it desirable to raise the scraper blade momentarily and then lower the same onto the pallet only when the front end of the pallet has moved a slight distance beyond the transverse vertical plane occupied by the scraping edge of the blade. For this purpose there is provided by the frame below each of the channels 10 and 11 a respective transverse slot 40, and received in each of these slots and pivoted intermediate its ends, as at 41, is a respective lever 42. The outer end of each said lever underlies a respective lift rod 43 receiving a slide journal in the frame, and the upper ends of these two lift rods each bear upon the underside of the scraper blade at a respective outer end thereof. The inner ends of said levers extend into spaced proximity of one another and each present a terminal pin 44 on which is journaled a roller 45. To depress these rollers and by such depression raise the lift rods and responsively elevate the scraper blade, there is secured to the front of the carriage a nose-piece 46 presenting inclined camming surfaces (see Fig. 3) upon its underside, the leading camming surface acting to raise the blade and the trailing camming surface then lowering the blade, both actions taking place during the momentary interval when the front end of the conveyed pallet is traversing the blade.

Designated by' 50 is a stop-dog permitting the pallet to move forwardly with the carriage but dropping into an interruptive position behind the pallet astthe carriage reaches the forward extreme of its reciprocatory, travel,

thus performing a stripping function dislodging the,

scraped pallet from the carriagetas the latter retraces its movement in the return stroke of reciprocation.

Pressure fluid for the operation of the hydraulic'rarn is fed'to. each of the two ends selectively from the. tank 52, discharging back to a reservoir 53. 54 denotes a pump, and 55 designates an electric motor for driving said pump. All controls are or may be electric. The machine is designed either for automatic or manual control, the former including twoswitches 56 and 57 (see Fig. 3) activated at a respective extreme of the carriages reciprocatory movement by a brush 58, such brush being hung from one'of the reach-arms so as to move with the carriage.

It is thought that the nature of the machine and the manner of its operation will have been clearly understood from the foregoing detailed description of my now-v preferred illustrated embodiment. It is self-evident that changes in the details of construction can be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language admits.

What I claim is: t

1 In a machine for cleaning pallets, an elongated 'frame, a reciprocally movable carriage mounted on the frame for travel therealong and adapted to have a pallet to be cleaned deposited thereon near one'extreme of the carriages reciprocatory movement, elongated scraping means normally occupying a position traversing the path travelled by a pallet conveyed-by the carriage for scraping the pallet as it travels on the carriage, a pair of yoke arms pivotally mounted at opposite sides of the frame and carrying said scrapingmeans therebetween, a pair Of upright posts connected to the frameat opposite ends of the scraping means, a strongback mounted by its ends on said posts and occupying a position above said scraping means, spring means seated between said strongback and the scraping means for yieldingly urging the latter downwardly, means for adjusting the load on said spring means, a pair of lift rods journal-mounted on the frame and arranged to swing said yoke arms upwardly, a pair of levers pivotally mounted on said frame; and, arranged to lift said lift rods by one of their ends when their other i ends are depressed, said other ends being located below the travel path of the carriage, cam means depending from the forward end of said carriage and arrangedto depress said other ends of the levers to responsively lift said scraping means out of the travel path of the conelled by a pallet conveyed by the carriage for scraping the pallet as it travels on the carriage, a pair of yoke arms pivotally mounted at opposite sides of the frame and carrying said scraping means therebetween, a pair of upright posts connected to the frame at opposite ends of the scraping means, a strongback slidably mounted by its ends on said posts and occupying a position above said scraping means, spring means seated between said strongback and the scraping means for yieldingly urging the latter downwardly, nuts threaded onto the upper ends of said posts for holding down the strongback and for adjusting the load on said spring means, a pair of lift rods journal-mounted-on the frame and arranged to swing said yoke arms upwardly, a pair of laterally extending levers pivotally mounted on said frame and arranged to lift said lift rods by their outer ends when their inner ends are depressed, said inner ends being located below the travel path of the carriage, a cam depending from the forward end of said carriage'and arranged to depress the inner ends of said levers to responsively lift said scraping means out of the travel path of the conveyed pallet in opposition to said spring means during the momentary interval in which the leading edge of said pallet'passes under said, scraping means, and hydraulic means for reciprocating said carriage. I

3. In a machine for cleaning pallets, an elongated frame, an, open-bottom magazine adapted toreceive a stack of pallets, a carriage mountedon the frame for reciprocatory traveltherealong between two extremes of travel in the rear-extreme of whichthe carriagecloses the open-bottom of the magazine and gives support to the lowermost pallet in the stack, means carried by the carriage acting to engage said lowermost pallet and cause the same to move with the carriage as the carriage travels to the forward extreme of said reciprocatory movement, means closing the open bottom of the magazine during the time interval necessary for said carriagetto move, from and again return totits said rear extreme position, ablade normally. occupying a position traversing the path travelled by a pallet conveyed by the carriage for scraping the pallet as it travelson 116 Q l' age, apair of yoke arms pivotally mounted at opposite sides of the frame and carrying said blade therebetween, a. pair of upright posts connected to the frame at oppositerends of the scraping means, a strongback mounted by, its ends on said posts and occupying' a position above said scrapinglmeans, spring means seated between said strongback and the blade for yieldingly urging the latter downwardly,- means;foradjusting the load on said spring means, a pair of lift rods journal-mounted on the fram'e'and arranged, toswing said yoke arms upwardly, a pair of levers pivotally mounted on saidtframe and arranged tolift said lift rods by one of their ends when their other endsare depressed, said other ends being. located below the travel path of thecarriage, a cam depending from the forward end of said carriage and arranged to depress said other ends of the levers. to responsively lift said blade outof the travel path of the conveyed pallet in opposition to said spring means during the momentary interval in which the leading edge of said pallet passes under said scraping means,

References Cited in the file of this patent UNITED STATES PATENTS 1,691,181 Coats Nov. 13, 1928 2,637,057 Moore May 5, 1953 2,752,621 Warsaw July 3, 1956 scraped pallet off 7 

